1. Field of the Invention
The present invention relates to a mobile communication terminal which performs radio communication with a base station by selectively using a plurality of communication modes.
2. Description of the Related Art
As a mobile communication terminal, a mobile communication terminal of a so-called dual mode type is available, which performs radio communication by selectively using an analog communication mode and a digital communication mode in accordance with the communication mode used by a base station. With the use of a terminal of the type, the user can perform radio communication with one terminal even in an area where only a base station conforming to an analog communication mode such as AMPS (Advanced Mobile Phone Service) is installed and an area where only a base station conforming to a digital communication mode such as the TDMA (Time Division Multiple Access) mode or CDMA (Code Division Multiple Access) mode is installed. That is, the mobile communication terminal is very convenient.
An increasing number of mobile communication terminals such as portable telephones and PDA (Personal Digital Assistants) have an electronic mail communication function as a well as a speech function. Electronic mail services generally include an Internet mail service via the Internet and a short message service (SMS) of transmitting electronic mail between mobile communication terminals in accordance with a protocol unique to a carrier. All these services use a digital communication mode.
For this reason, when a user tries to transmit/receive electronic mail by using a mobile communication terminal of the dual mode type described above, he/she cannot transmit or receive any electronic mail while a base station conforming to an analog communication mode is captured. In such a case, the user must try to switch to a digital communication mode or transmitting or receiving operation again after the communication mode is switched to the digital communication mode. That is, cumbersome operation is required.